Garage Door Cable Replacement: preparing for the visit

The door went up as usual this morning, then stopped a third of the way with one corner higher than the other. It is wedged at an angle in the opening, the opener is humming, and nothing you press will move it.

Worth answering before the call

Is anything stored close to the door or under the spring shaft? Can you see a cable hanging loose, frayed, or wound around the shaft? Is there rust on the cables or brackets near the floor?

Can I lift the door by hand while a cable is off?

Leave it. With one cable slack the door is being carried on one side only, so it is unbalanced and may bind or drop unevenly when moved. The technician arrives with clamps and a method for taking the door's weight before anything is moved, and that is the moment to lift it. Until then a stationary door is exactly what you want.

How do I tell a cable problem from a spring problem?

Look above the door with it closed. A torsion spring that has broken shows a clear gap in the coil, and both cables usually go slack together because nothing is turning the shaft. A cable problem tends to show on one side only: a frayed length, a coil of loose cable, or one corner sitting higher. Either way the technician inspects both, since a weak spring is a common reason a cable fails.